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  1. #1
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    Default Grounding Service Panel to Gas Line

    Inspected house today built in 1956. The panel had been update. The problem is there was a ground wire on the neutral connecting to a natural gas pipe below panel. There was also a rod in ground outside at the meter base. I did notice the gas line was bonded to the water heater cold and hot pipes. Did the electrician mistakenly think the cast iron gas line was a water pipe? This is the first time I had seen this.

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  2. #2
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    Default Re: Grounding Service Panel to Gas Line

    While this may seem like it is only semantics, the panel is not grounded to the gas pipe, the gas pipe is bonded to ground in the panel.

    I say that because there are other grounding conductors which go somewhere else, presumably one goes to metal water pipe and another goes to a grounding electrode (which may be, or may have been, an underground metal water pipe).

    The gas pipe is not being - should not be - used as a grounding electrode. The gas pipe should be bonded to ground to ground out any voltage which may be on the gas pipe.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  3. #3
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Sam Morris View Post
    Inspected house today built in 1956. The panel had been update. The problem is there was a ground wire on the neutral connecting to a natural gas pipe below panel. There was also a rod in ground outside at the meter base. I did notice the gas line was bonded to the water heater cold and hot pipes. Did the electrician mistakenly think the cast iron gas line was a water pipe? This is the first time I had seen this.
    Just another small point. The gas pipe is black iron, or steel. It is not cast iron.


  4. #4
    Tim de Vries's Avatar
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Jerry Peck View Post
    While this may seem like it is only semantics, the panel is not grounded to the gas pipe, the gas pipe is bonded to ground in the panel.

    I say that because there are other grounding conductors which go somewhere else, presumably one goes to metal water pipe and another goes to a grounding electrode (which may be, or may have been, an underground metal water pipe).

    The gas pipe is not being - should not be - used as a grounding electrode. The gas pipe should be bonded to ground to ground out any voltage which may be on the gas pipe.
    Isn't the bonding for gas/water (metal inside house to plastic) supposed to be bonded to ground not neutral?


  5. #5
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Tim de Vries View Post
    Isn't the bonding for gas/water (metal inside house to plastic) supposed to be bonded to ground not neutral?
    Being as the grounds and neutrals are in the same terminal bar, I am presuming that is the service equipment. Being service equipment the neutrals are bonded to ground, so using that bar grounds the neutrals to ground and bonds the gas pipe to ground.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  6. #6
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Jerry Peck View Post
    Being as the grounds and neutrals are in the same terminal bar, I am presuming that is the service equipment. Being service equipment the neutrals are bonded to ground, so using that bar grounds the neutrals to ground and bonds the gas pipe to ground.
    Yeah, Tim is in Canada, where neutrals and grounds are separated in the branch circuit portion of the service panel. Branch circuits are always kept separate from service conductors as well.
    So we would never see something like that here, or would call it out as amateur work, no offense intended. It would not comply with the CEC.

    John Kogel, RHI, BC HI Lic #47455
    www.allsafehome.ca

  7. #7
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by John Kogel View Post
    Yeah, Tim is in Canada, ...
    Thanks, John, I missed looking at where he was from ... up yonder.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  8. #8
    Tim de Vries's Avatar
    Tim de Vries Guest

    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Jerry Peck View Post
    Thanks, John, I missed looking at where he was from ... up yonder.
    Yep, just snow and igloos and deer up here. I'm building my own place and I'm not an electrician, but our service connectors are in one section that's all separate from the branch circuits and the grounds are attached to lugs(?) on the enclosure. The neutrals are connected to the neutral bus bar. In my panel I only have a few ground connectors and am not sure if I can just twist a bunch together to have them all connected securely but will get that sorted.


  9. #9
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    Default Re: Grounding Service Panel to Gas Line

    John, Tim,

    Unless I missed it, neither of you mentioned or addressed the condition I referred to as why the gas pipe is bonded to the terminal bar wit neutrals and grounds as not being permitted (other than saying that in Canada they are in separate compartments) when the photo shows the neutrals and grounds in the same terminal bar.

    As that is not allowed in Canada, I would have thought you would have stated that what is shown in the photo is not allowed.

    Did I miss where you pointed out that what the photo shows is not allowed and needs to be corrected? Just curious.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  10. #10
    Tim de Vries's Avatar
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Jerry Peck View Post
    John, Tim,

    Unless I missed it, neither of you mentioned or addressed the condition I referred to as why the gas pipe is bonded to the terminal bar wit neutrals and grounds as not being permitted (other than saying that in Canada they are in separate compartments) when the photo shows the neutrals and grounds in the same terminal bar.

    As that is not allowed in Canada, I would have thought you would have stated that what is shown in the photo is not allowed.

    Did I miss where you pointed out that what the photo shows is not allowed and needs to be corrected? Just curious.
    My bad.

    In Canada, to the best of my knowledge, what is shown is not acceptable. All metal piping within the structure is to be bonded to ground with a #6 bare copper from CSA or UL approved ground clamp suitable for the type of location (wet, damp or dry) to ground (at panel, growing rod, plate or buried metal piping). Bonding to water piping is not acceptable where the water enters through plastic pipe. Buried metal piping may be allowed provided the diameter and buried length provide sufficient surface area for grounding requirements. Metal piping connected to plastic must be bonded to ground.

    in Canada, it appears it may not be acceptable. I would err on the side of caution.

    National, state and local codes should take precedence in every case.


  11. #11

    Default Re: Grounding Service Panel to Gas Line

    The CEC requires bonding of metal gas piping. It doesn't matter if you bond it to metal water piping that's already bonded, or to the service neutral. ALL THREE components are connected together no matter where you do it.

    From http://www.municipalaffairs.alberta....EC-10-rev8.pdf

    Rule 10-406 Non-electrical Equipment
    Bonding as required by the rule is provided by connecting a continuous No. 6 AWG copper conductor, using suitable fittings or lugs, from the non-electrical equipment to the electrical service ground. When bonding soft copper propane lines and other similar tubing, care should be taken to ensure the piping is not damaged, and the use of straps as per Rule 10-614(2) for this application is recommended.
    Bonding of Gas Piping Systems
    Bonding of gas piping systems should not interfere with any cathodic protection forming part of the gas piping system. The bonding of the gas line should therefore be made on the consumer side of the gas meter. Common practice in residential applications has been to bond the gas piping system to the cold water pipe at the hot-water tank. With the increasing use of plastic water lines, it is recommended that the gas piping system be bonded to the main distribution panel or the grounding conductor or the grounding electrode (see also STANDATA item 10-700).


  12. #12
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Mark Cramer View Post
    ... or to the service neutral.
    .
    .
    Rule 10-406 Non-electrical Equipment
    ... to the electrical service ground.
    In the states that would be the same place, in Canada the neutral is in a separate compartment, which would be required there?

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  13. #13
    Tim de Vries's Avatar
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Jerry Peck View Post
    In the states that would be the same place, in Canada the neutral is in a separate compartment, which would be required there?
    Electrical Code Simplified 2007, pg 52(f)
    Rule 10-406(2)(3)(4)

    "... This conductor connects to each of the metal piping systems with a regular ground clamp or a grounding strap as shown in the illustration, then it connects to the service grounding conductor at any convenient point which will remain accessible for inspection when future load changes are made.​"


  14. #14
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Tim de Vries View Post
    Electrical Code Simplified 2007, pg 52(f)
    Rule 10-406(2)(3)(4)

    "... This conductor connects to each of the metal piping systems with a regular ground clamp or a grounding strap as shown in the illustration, then it connects to the service grounding conductor at any convenient point which will remain accessible for inspection when future load changes are made.​"
    "then it connects to the service grounding conductor"

    Tim,

    That would be the conductor which goes to the grounding system, which we refer to as the grounding electrode conductor which connects the grounding of the service equipment panel to the grounding electrodes ... would that be an appropriate description?

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  15. #15
    Tim de Vries's Avatar
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Jerry Peck View Post
    "then it connects to the service grounding conductor"

    Tim,

    That would be the conductor which goes to the grounding system, which we refer to as the grounding electrode conductor which connects the grounding of the service equipment panel to the grounding electrodes ... would that be an appropriate description?
    Oh geez, I'm not an inspector but if that's what it's called then I'd say that's right based on what's been presented.


  16. #16
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    Default Re: Grounding Service Panel to Gas Line

    I just came across this and thought it would be helpful for anyone research the subject (it might also help to start some fights too )

    Is Gas Pipe Grounding Legal? | Code Basics content from Electrical Construction & Maintenance (EC&M) Magazine


  17. #17
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    Default Re: Grounding Service Panel to Gas Line

    Quote Originally Posted by Dwight Doane View Post
    I just came across this and thought it would be helpful for anyone research the subject (it might also help to start some fights too )

    Is Gas Pipe Grounding Legal? | Code Basics content from Electrical Construction & Maintenance (EC&M) Magazine
    No problem with that link ... other than it is 15 year old information.

    So let's start back BEFORE that 15 year old information: (bold and underlining are mine)
    - From the 1996 NEC
    - - 250-80. Bonding of Piping Systems and Exposed Structural Steel.
    - - - (b) Other Metal Piping. Interior metal piping that may become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used. - - - - - The bonding jumper shall be sized in accordance with Table 250-95 using the rating of the circuit that may energize the piping.
    - - - - The equipment grounding conductor for the circuit that may energize the piping shall be permitted to serve as the bonding means.
    - - - - (FPN): Bonding all piping and metal air ducts within the premises will provide additional safety.


    - - - From Table 250-95. Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment
    - - - - for 15 amp circuits - 14 AWG bonding jumper size
    - - - - for 20 amp circuits - 12 AWG bonding jumper size
    - - - - for 30 amp circuits - 10 AWG bonding jumper size


    - From the 1999 NEC
    - - 250-104. Bonding of Piping Systems and Exposed Structural Steel
    - - - x(b) Metal Gas Piping. Each aboveground portion of a gas piping system upstream from the equipment shutoff valve shall be electrically continuous and bonded to the grounding electrode system.
    - - - (c) Other Metal Piping. Interior metal piping that may become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used. - - - - - The bonding jumper shall be sized in accordance with Table 250-122 using the rating of the circuit that may energize the piping.
    - - - - The equipment grounding conductor for the circuit that may energize the piping shall be permitted to serve as the bonding means.
    - - - - FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.

    - - - [The "x" in front of (b) is a bookmark which links to the following:]
    - - - - xA-250-104(b) National Fuel Gas Code, NFPA 54-1996 Paragraph 3.14(a)
    - - - [Thus (b) is basically just pointing to where that wording is taken from, and "(c) Other Metal Piping." is still an applicable section for gas piping.]




    - From the 2002 NEC
    - - 250.104 Bonding of Piping Systems and Exposed Structural Steel.
    - - - (B) Other Metal Piping. Where installed in or attached to a building or structure, metal piping system(s), including gas piping, that may become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122 using the rating of the circuit that may energize the piping system(s). The equipment grounding conductor for the circuit that may energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.
    - - - FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.
    - - - [Note that the "x(b)" wording is gone and we are left with what was there before the "x(b)" ... "(b) Other Metal Piping." for use with gas piping.]


    - From the 2005 NEC
    - - 250.104 Bonding of Piping Systems and Exposed Structural Steel.
    - - - (B) Other Metal Piping. Where installed in or attached to a building or structure, metal piping system(s), including gas piping, that is likely to become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.
    - - - FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.

    - From the 2008 NEC:
    - - 250.104 Bonding of Piping Systems and Exposed Structural Steel.
    - - - (B) Other Metal Piping. Where installed in or attached to a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.
    - - - FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.

    Okay, let's now go back to that article: (bold and underlining are mine)
    "You should size the bonding jumper connecting and bonding the metal gas piping to the grounding electrode system as noted in Table 250-66 of the NEC; based on the largest ungrounded service phase conductor. You should size the conductor just as you would size it if it were a metal water pipe isolated from earth ground because of a nonmetallic underground water supply system.

    However, some disagree. They believe you should size it from Table 250-122, determined by the size of the overcurrent protection device ahead of the circuit. The only problem we have with this concept and method of sizing is which protective device should you use: the service device, feeder device, or branch-circuit device? Due to this uncertainty, we feel the need for a proposal for the 2002 NEC to clarify which Table to use when sizing this conductor. Depending on where you're working, you should check with the AHJ for their official interpretation."

    The bonding of the water piping is based not based on the same thing that bonding of gas piping is based on - the bonding jumper size for gas piping is based on the circuit which would likely energize the metal gas piping ... the circuit supplying the gas appliance itself. Thus, the largest ungrounded phase conductor would be the ungrounded conductor of that circuit. And the equipment grounding conductor is already properly sized for that size ungrounded conductor ... and the equipment grounding conductor is also already connected back to the grounding electrode system (by being bonded to it at the service equipment).

    That's why the tables for sizing the bonding conductor for gas piping show:
    - for 15 amp circuits - 14 AWG bonding jumper size
    - for 20 amp circuits - 12 AWG bonding jumper size
    - for 30 amp circuits - 10 AWG bonding jumper size
    ... the same size as the equipment grounding conductor for a circuit of that rating.

    I really do not see what the problem is, what the confusion is, or why there is a misunderstanding of what is required by the code ... the way back to before that article was published to toward current day (I stopped at 2008 as I was tired of repeating it over and over and over again).

    So ... if someone wants to start a fight over it ... let them first tell us what it is that they do not understand about what the code says. THEN we can .

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

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